1. Technical Field
The present invention relates generally to antennas; and, more particularly, it relates to a diagonal dual-polarized broadband horn antenna.
2. Related Art
Conventional broadband horn antennas used in electromagnetic test systems are commonly limited in operating frequency ranges of approximately 500 MHz to 18 GHz. Generally speaking, linear dimensions of a conventional antenna vary inversely with the operating frequency range. To try to operate at much lower frequency ranges, a conventional approach has been to increase the overall size of a horn antenna. This has proven to be very difficult in terms of implementation. For example, the size constraints of a horn antenna, for proper use in a test system, are considerable. In addition, as the size of a horn antenna increases, thereby allowing a lower operating frequency range, the weight of the horn antenna also increases. This also encumbers the ease with which the horn antenna is used in various electromagnetic test systems. The size, weight, and bulkiness of existing horn antennas are all considerations that limit their ease of implementation for use in test systems. Moreover, there is no easy way in which these conventional horn antennas can be mounted within existing shielded test chambers as part of the shielded enclosure. Additional manufactured fixtures or positioners must be made in order to integrate the horn antenna into the test chamber. Sometimes, these additional fixtures to the horn antenna may compromise the overall performance of the test system by the presence of additional unwanted signals introduced by them.
There are primarily two approaches known in the art of manufacturing broadband horn antennas under the conventional approach. FIGS. 1A-1D show prior art implementations of broadband horn antennas. FIG. 1A is a system diagram illustrating a conventional embodiment of a square broadband horn antenna 100A, and FIG. 1B is another perspective of the square broadband horn antenna 100B of the FIG. 1A. Line ridges 110 are aligned along the side wall segments of the square broadband horn antenna 100A. The sides of the square broadband horn antenna 100A (and the square broadband horn antenna 100B) are commonly metallic sides 120 as known in the art of electromagnetic testing. Connectors 130 are provided to energize the square broadband horn antenna 100A (and the square broadband horn antenna 100B). To allow operating lower operational frequency ranges, the size of the aperture of the size of the square broadband horn antenna 100A (and the square broadband horn antenna 100B) must be increased accordingly.
As mentioned above, the sizes of most conventional broadband horn antennas generally limits their lower end of the operating frequency ranges to approximately 500 MHz given the considerations of having a size that allows practical emplacement, removal, and modification of test facilities to accommodate them. While the conventional designs of broadband horn antennas is theoretically scalable to accommodate lower frequency operating ranges, the actual scaling of broadband horn antennas to larger sizes that allow for this type of operation presents other impediments that simply make such large broadband horn antenna designs. For example, the large and bulky size significantly encumbers movement of the broadband horn antenna to such a degree that their use in a test facility where interchange of test devices, the absorbers used in the test facility, and the broadband horn antennas themselves, can be commonplace. Moreover, the weight of such large and bulky broadband horn antennas additionally encumbers their use for lower operating frequency ranges.
FIG. 1C is a system diagram illustrating a conventional embodiment of a circle broadband horn antenna 100C, and FIG. 1D is another perspective of the circle broadband horn antenna 100C of the FIG. 1C. Line ridges 140 are aligned along the interior of the circle broadband horn antenna 100C. The sides of the circle broadband horn antenna 100C (and the circle broadband horn antenna 100D) are commonly metallic sides 150 as known in the art of electromagnetic testing. Connectors 160 are provided to energize the circle broadband horn antenna 100C (and the circle broadband horn antenna 100D). To allow operating lower operational frequency ranges, the size of the aperture of the size of the circle broadband horn antenna 100C (and the circle broadband horn antenna 100D) must be increased accordingly, as mentioned above in square embodiments of conventional broadband horn antennas. The many deficiencies of the square embodiments are equally applicable with respect to the circle embodiments of broadband horn antennas. In addition, the manufacturing complexity of the circular broadband horns results in much higher cost of this particular broadband horn antenna that is designed to operate at lower operating frequencies. As a result, the available commercial product of this type of horn is limited to operating frequencies above 2 GHz. The lower frequency ranges simply cannot be met using this design.
Further limitations and disadvantages of conventional and traditional systems will become apparent to one of skill in the art through comparison of such systems with the present invention as set forth in the remainder of the present application with reference to the drawings.
Various aspects of the present invention can be found in a diagonal dual-polarized broadband horn antenna. The diagonal dual-polarized broadband horn antenna includes, among other things, a square cavity having a number of corners, a diagonal line ridge located at one of 5 the corners, and a number of electrical connectors, mounted on the diagonal dual-polarized broadband horn antenna, that receive a signal that is used to energize the diagonal line ridge to generate electromagnetic illumination.
In certain embodiments of the invention, more than one diagonal line ridge is employed. The diagonal dual-polarized broadband horn antenna also includes a tuning bar, mounted on the square cavity, that is operable to improve matching conditions of frequencies emanating from the diagonal dual-polarized broadband horn antenna in a common direction. More than one tuning bar is used in some embodiments of the inventions. The square cavity is made of any number of materials including a dielectric material and a metallic material. One, some, or all of the electrical connectors is a radio frequency connector. The diagonal dual-polarized broadband horn antenna also includes an integrated, shielded mounting flange located at an end of the diagonal dual-polarized broadband horn antenna. The diagonal line ridge has any number of shapes including a smooth shape. The diagonal dual-polarized broadband horn antenna is operable for installation on a shield line of a shielded anechoic test chamber among other types of test chambers types.
Other aspects of the present invention can be found in a diagonal dual-polarized broadband horn antenna. The diagonal dual-polarized broadband horn antenna includes, among other things, an aperture having a corner, and a diagonal line ridge that is positioned at the corner.
In certain embodiments of the invention, the aperture further also includes three additional corners and three additional diagonal line ridges. Each of the three additional diagonal line ridges is positioned at one of the three additional comers. The diagonal line ridge is of any number of types of shapes including a tapered ridge shape. The diagonal dual-polarized broadband horn antenna also includes a cavity and a tuning bar. The tuning bar is mounted on the cavity and is operable to improve matching conditions for frequencies emanating from the diagonal dual-polarized broadband horn antenna in a common direction. More than one tuning bar is used in some embodiments of the inventions. The diagonal dual-polarized broadband horn antenna also includes at least two input feeds, on the mounting flange, that are operable to permit simultaneous measurements for dual polarizations emanating from the diagonal dual-polarized broadband horn antenna. The diagonal dual-polarized broadband horn antenna also includes a cavity that is made of any number of materials including a dielectric material and a metallic material. The diagonal dual-polarized broadband horn antenna is operable for installation on a shield line of a shielded anechoic test chamber among other types of test chambers types.
Other aspects of the present invention can be found in a diagonal dual-polarized broadband horn antenna. The diagonal dual-polarized broadband horn antenna includes a square cavity, a mounting flange coupled to the square cavity, and two input feeds, on the mounting flange, that are operable to permit simultaneous measurements for dual polarizations emanating from the diagonal dual-polarized broadband horn antenna.
In certain embodiments of the invention, the diagonal dual-polarized broadband horn antenna is operable to generate electromagnetic illumination having a frequency range of approximately 100 MHz to approximately 18 GHz. The square cavity includes a number of corners and a number of diagonal line ridges. Each of the diagonal line ridges is positioned at one of the comers. The square cavity is made of any number of materials including a dielectric material. The diagonal dual-polarized broadband horn antenna also includes a tuning bar, mounted on the square cavity, that is operable to improve a matching condition for frequencies emanating from the diagonal dual-polarized broadband horn antenna in a common direction. More than one tuning bar is used in some embodiments of the inventions. The diagonal dual-polarized broadband horn antenna is operable for installation on a shield line of a shielded anechoic test chamber among other test chamber types.
Other aspects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.